1. Field of the Invention
The present invention relates generally to fluid reaction surfaces, and more specifically to turbine blade with a cooling circuit in the blade tip.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
In the prior art, blade tip cooling is accomplished by drilling holes into the upper extremes of the serpentine flow coolant passages from both the pressure and suction side surfaces near the blade tip edge and the top surface of the squealer cavity. The cooling flow distribution and pressure ratio across these film cooling holes for the airfoil pressure and suction sides as well as the tip region is subject to severe secondary flow field, which translates into a large quantity of film cooling holes and cooling flow that is required for cooling the blade tip peripheral. FIG. 1 shows a prior art turbine blade tip cooling hole arrangement on the pressure side and FIG. 2 shows the same prior art turbine blade tip cooling hole arrangement for the suction side of the blade tip.
It is an object of the present invention to provide for a blade tip cooling circuit that will provide adequate blade tip cooling with less cooling air flow.
It is another object of the present invention to provide for a turbine blade with a blade tip cooling circuit that provides both impingement cooling and vortex flow cooling for the blade tip circuit.